Analysis of kinematic correlations in faults and focal mechanisms with GIS and Fortran programs

The kinematic correlation between faults and focal mechanisms can be quantified using scalar (vector and tensor product) or geometric (rotation pole and angle) measures of the similarity of their orientations. The statistical properties of the correlation may help characterise the spatio-temporal properties of natural datasets and test their congruence with theoretical models. This paper describes GIS and Fortran 90/95 tools for analysing the kinematic correlation of faults, and for simulating fault movements in a homogeneous stress field. As an example, we analyse the Umbria-Marche 1997 seismic sequence with these tools; our results show a positive spatial correlation of seismic events that increases with time following the mainshocks.